Walk through Amos, verse by verse, with the great Bible Commentaries of Matthew Henry (1662 - 1714) & Adam Clarke (1760 - 1832)
1:11
Thus saith the LORD; For three transgressions of Edom, and for four, I will not turn away the punishment thereof; because he did pursue his brother with the sword, and did cast off all pity, and his anger did tear perpetually, and he kept his wrath for ever: KJV
For three transgressions of Edom - That the Edomites were always implacable enemies of the Jews, is well known; but most probably that which the prophet has in view was the part they took in distressing the Jews when Jerusalem was besieged, and finally taken, by the Chaldeans.
Concerning Edom, the posterity of Esau.
Their peculiar sin was an unmerciful, unwearied, pursuit of the people of God, and their taking all advantages against them to do them a mischief, v. 11. He did pursue his brother with the sword, not only of old, when the king of Edom took up arms to oppose the children of Israel’s passage through his border (Numbers 20:18), Edom’s malice was unnatural, for thus he pursued his brother, whom he ought to have protected:
